LOS ANGELES — Modern Hollywood has never been much of a playground for aging actors.

But lately, the kids have been downright snotty to the Geritol generation.

Over the past two weeks, former big-screen titans Arnold Schwarzenegger, 65, Sylvester Stallone, 66, and Al Pacino, 72, have not only seen their films open to less-than-stellar numbers, they're not even cracking the top 5.

The decline has been dramatic:

* Stallone's Bullet to the Head, a throwback to the shoot-em-ups of the '80s and '90s, mustered a feeble $4.5 million at the box office this past weekend, less than half what analysts expected.

* The same weekend, Stand Up Guys, an all-star collection of Oscar-winning veterans including Pacino, Christopher Walken, 69, and Alan Arkin, 78, did a paltry $1.5 million. While the film saw only limited release, it came in 17th place, two spots behind the gross-out comedy Movie 43 (already a flop in its second week).

* Schwarzenegger's action film The Last Stand, which received some of the strongest reviews of the actor's career, dropped an astounding 88% from its Jan. 18 opening weekend, one of the largest declines in Hollywood history. It did $265,000 this weekend, behind a limited-run film festival of 2013's Oscar-nominated short films.

"Right now, it seems, no young people are interested in these guys, at least by themselves" says Jeff Bock, chief analyst for box office trackers Exhibitor Relations. "The only way people will see them is if they band together as teams."

And even that appeal is waning.

The Expendables, the 2010 action film starring Stallone, Jason Statham, now 45, Jet Li, 49, and Mickey Rourke, 60, had analysts thinking comeback when the movie racked up $103 million.

"We thought these guys were viable as a multi-pack," Bock says.

And while last summer's The Expendables 2 reunited the cast (and added some names like Chuck Norris, 72, and Jean-Claude Van Damme, 52), the movie saw diminished returns of $85 million, unusual for a high-profile sequel (and an economic flub for a $100 million movie).

For their part, the stars say they'll keep doing what they know.

"I cannot be happy if I'm not useful. It's that simple," Schwarzenegger says. "I get up and I have work to do. I am happy on a movie set. I wouldn't be happy to sit back. And do what? That's not my style. I will be doing things until I'm six feet under."

The next high-profile test comes Feb. 14, when Bruce Willis, 57, stars in A Good Day to Die Hard, the fifth film in the Die Hard franchise. Willis says he pays no mind to box office predictions, or laments about his franchise's quarter century at the multiplex: "No one can see the future. And if they say they can, they are kidding you. I've talked to psychics and even they cannot predict the future."

As for his series being long in the tooth, Willis says "You only start thinking about 25 years when you have these anniversaries and everyone reminds you."

Analysts say Day stands a better chance than its AARP-qualified predecessors because it's part of an established franchise. Since the series began in 1988, the movies have averaged $109 million apiece, according to the website BoxOfficeMojo.com.

The downward trend has forced aging actors (in Hollywood terms, think anyone 40 and older) to two venues: television and Oscar season.

Oscar season offers a respite for some established stars, as studios briefly invade television's dominance of dramas for biopics and serious storytelling.

Even with a graying cast that includes Daniel Day-Lewis, 55, Tommy Lee Jones, 66, and Sally Field, 66,Lincoln has mustered an impressive $171 million. And while Ben Affleck, 40, is hardly geriatric, his Argo co-stars Arkin, John Goodman, 60, and Bryan Cranston, 56, haven't hurt the film's ascent to $120 million.

"It's heartening to see people actually responding to established acting in good stories," says Jeremy Kay, U.S. editor of the London-based trade publication Screen International. "Of course, Oscar season doesn't last forever."

Nor, say analysts, will aging stars' big-screen life expectancy. Bock says part of the trouble for aging actors is that the genre that once fed them — shoot-em-ups, dialogue-heavy films — have given way to zombie flicks and comic book movies.

"Unfortunately for the (older) actors, the novelty of all-star teams is going to wear off pretty quickly," Bock says. "I'm not sure what happens to them, unless they find another gimmick."